There were also some people who expected Mostafa Moeen, the most controversial reformist candidate, to be disqualified as well.
The boycott was announced one day after more than a third of the Parliament's members resigned to protest a ban on hundreds of reformist candidates.
He was a reformist candidate for the 2009 presidential election and eventually the leader of the opposition in the post-election unrest.
First results from yesterday's elections in 5 Soviet republics show reformist and separatist candidates have again done well.
Some observers considered Ong as the reformist candidate because the two other candidates each represented the then president and premier's factions respectively.
He believes some reformist candidates are wrongly kept from running.
He would also have had to get a number of voters who had previously voted for a reformist candidate in 2005 to defect to him.
Centrist, reformist candidates appear to have done worse than expected, according to political analysts.
Assisting the conservative victory was the disqualification of about 2500 reformist candidates earlier in January.
Nearly 90 percent of reformist candidates have been disqualified from the election.